This book deals with the Causes of Physical Degeneracy and Town-Life as a Cause of Degeneracy. Whether the human race is degenerating, and, if so, by what causes, are questions of much speculative interest to scientific thinkers, and of much practical interest to each father and mother in the community. The subject is complicated by many conditions. Physical health and vigor, and mental strength and power, are to a great degree a matter of hereditary transmission, over which the individual has no control. Yet, taking our natures as they are, we can renovate, reinvigorate, and advance them by attentive study of and conformity to the laws upon which health and vigor are based. I propose in the present work briefly to glance at the chief physical agencies—air, exercise, clothing, food, and rest—and at some of the mental and moral influences, by the bad or good employment of which the physical stock is deteriorated or improved.